[PATCH 1/6] mdev: class id support
Jason Wang
jasowang at redhat.com
Mon Sep 23 13:03:26 UTC 2019
Mdev bus only supports vfio driver right now, so it doesn't implement
match method. But in the future, we may add drivers other than vfio,
one example is virtio-mdev[1] driver. This means we need to add device
class id support in bus match method to pair the mdev device and mdev
driver correctly.
So this patch adds id_table to mdev_driver and class_id for mdev
parent with the match method for mdev bus.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
Documentation/driver-api/vfio-mediated-device.rst | 7 +++++--
drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +-
drivers/s390/cio/vfio_ccw_ops.c | 2 +-
drivers/s390/crypto/vfio_ap_ops.c | 3 ++-
drivers/vfio/mdev/mdev_core.c | 14 ++++++++++++--
drivers/vfio/mdev/mdev_driver.c | 14 ++++++++++++++
drivers/vfio/mdev/mdev_private.h | 1 +
drivers/vfio/mdev/vfio_mdev.c | 6 ++++++
include/linux/mdev.h | 7 ++++++-
include/linux/mod_devicetable.h | 8 ++++++++
samples/vfio-mdev/mbochs.c | 2 +-
samples/vfio-mdev/mdpy.c | 2 +-
samples/vfio-mdev/mtty.c | 2 +-
13 files changed, 59 insertions(+), 11 deletions(-)
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 25eb7d5b834b..0e052072e1d8 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -102,12 +102,14 @@ structure to represent a mediated device's driver::
* @probe: called when new device created
* @remove: called when device removed
* @driver: device driver structure
+ * @id_table: the ids serviced by this driver.
*/
struct mdev_driver {
const char *name;
int (*probe) (struct device *dev);
void (*remove) (struct device *dev);
struct device_driver driver;
+ const struct mdev_class_id *id_table;
};
A mediated bus driver for mdev should use this structure in the function calls
@@ -116,7 +118,7 @@ to register and unregister itself with the core driver:
* Register::
extern int mdev_register_driver(struct mdev_driver *drv,
- struct module *owner);
+ struct module *owner);
* Unregister::
@@ -163,7 +165,8 @@ A driver should use the mdev_parent_ops structure in the function call to
register itself with the mdev core driver::
extern int mdev_register_device(struct device *dev,
- const struct mdev_parent_ops *ops);
+ const struct mdev_parent_ops *ops,
+ u8 class_id);
However, the mdev_parent_ops structure is not required in the function call
that a driver should use to unregister itself with the mdev core driver::
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 23aa3e50cbf8..19d51a35f019 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1625,7 +1625,7 @@ static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
return -EFAULT;
intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
- return mdev_register_device(dev, &intel_vgpu_ops);
+ return mdev_register_vfio_device(dev, &intel_vgpu_ops);
}
static void kvmgt_host_exit(struct device *dev)
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index f0d71ab77c50..246ff0f80944 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -588,7 +588,7 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
int vfio_ccw_mdev_reg(struct subchannel *sch)
{
- return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
+ return mdev_register_vfio_device(&sch->dev, &vfio_ccw_mdev_ops);
}
void vfio_ccw_mdev_unreg(struct subchannel *sch)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 5c0f53c6dde7..7487fc39d2c5 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1295,7 +1295,8 @@ int vfio_ap_mdev_register(void)
{
atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
- return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
+ return mdev_register_vfio_device(&matrix_dev->device,
+ &vfio_ap_matrix_ops);
}
void vfio_ap_mdev_unregister(void)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index b558d4cfd082..a02c256a3514 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -135,11 +135,14 @@ static int mdev_device_remove_cb(struct device *dev, void *data)
* mdev_register_device : Register a device
* @dev: device structure representing parent device.
* @ops: Parent device operation structure to be registered.
+ * @id: device id.
*
* Add device to list of registered parent devices.
* Returns a negative value on error, otherwise 0.
*/
-int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
+int mdev_register_device(struct device *dev,
+ const struct mdev_parent_ops *ops,
+ u8 class_id)
{
int ret;
struct mdev_parent *parent;
@@ -175,6 +178,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
parent->dev = dev;
parent->ops = ops;
+ parent->class_id = class_id;
if (!mdev_bus_compat_class) {
mdev_bus_compat_class = class_compat_register("mdev_bus");
@@ -208,7 +212,13 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
put_device(dev);
return ret;
}
-EXPORT_SYMBOL(mdev_register_device);
+
+int mdev_register_vfio_device(struct device *dev,
+ const struct mdev_parent_ops *ops)
+{
+ return mdev_register_device(dev, ops, MDEV_ID_VFIO);
+}
+EXPORT_SYMBOL(mdev_register_vfio_device);
/*
* mdev_unregister_device : Unregister a parent device
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 0d3223aee20b..b70bbebc9dd3 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -69,8 +69,22 @@ static int mdev_remove(struct device *dev)
return 0;
}
+static int mdev_match(struct device *dev, struct device_driver *drv)
+{
+ unsigned int i;
+ struct mdev_device *mdev = to_mdev_device(dev);
+ struct mdev_driver *mdrv = to_mdev_driver(drv);
+ const struct mdev_class_id *ids = mdrv->id_table;
+
+ for (i = 0; ids[i].id; i++)
+ if (ids[i].id == mdev->parent->class_id)
+ return 1;
+ return 0;
+}
+
struct bus_type mdev_bus_type = {
.name = "mdev",
+ .match = mdev_match,
.probe = mdev_probe,
.remove = mdev_remove,
};
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index 7d922950caaf..e58b07c866b1 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -22,6 +22,7 @@ struct mdev_parent {
struct list_head type_list;
/* Synchronize device creation/removal with parent unregistration */
struct rw_semaphore unreg_sem;
+ u8 class_id;
};
struct mdev_device {
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index 30964a4e0a28..fd2a4d9a3f26 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev)
vfio_del_group_dev(dev);
}
+static struct mdev_class_id id_table[] = {
+ { MDEV_ID_VFIO },
+ { 0 },
+};
+
static struct mdev_driver vfio_mdev_driver = {
.name = "vfio_mdev",
.probe = vfio_mdev_probe,
.remove = vfio_mdev_remove,
+ .id_table = id_table,
};
static int __init vfio_mdev_init(void)
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 0ce30ca78db0..3ebae310f599 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -118,6 +118,7 @@ struct mdev_type_attribute mdev_type_attr_##_name = \
* @probe: called when new device created
* @remove: called when device removed
* @driver: device driver structure
+ * @id_table: the ids serviced by this driver.
*
**/
struct mdev_driver {
@@ -125,6 +126,7 @@ struct mdev_driver {
int (*probe)(struct device *dev);
void (*remove)(struct device *dev);
struct device_driver driver;
+ const struct mdev_class_id *id_table;
};
#define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver)
@@ -135,7 +137,8 @@ const guid_t *mdev_uuid(struct mdev_device *mdev);
extern struct bus_type mdev_bus_type;
-int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
+int mdev_register_vfio_device(struct device *dev,
+ const struct mdev_parent_ops *ops);
void mdev_unregister_device(struct device *dev);
int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
@@ -145,4 +148,6 @@ struct device *mdev_parent_dev(struct mdev_device *mdev);
struct device *mdev_dev(struct mdev_device *mdev);
struct mdev_device *mdev_from_dev(struct device *dev);
+#define MDEV_ID_VFIO 1 /* VFIO device */
+
#endif /* MDEV_H */
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 5714fd35a83c..f32c6e44fb1a 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -821,4 +821,12 @@ struct wmi_device_id {
const void *context;
};
+/**
+ * struct mdev_class_id - MDEV device class identifier
+ * @id: Used to identify a specific class of device, e.g vfio-mdev device.
+ */
+struct mdev_class_id {
+ __u16 id;
+};
+
#endif /* LINUX_MOD_DEVICETABLE_H */
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index ac5c8c17b1ff..71a4469be85d 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1468,7 +1468,7 @@ static int __init mbochs_dev_init(void)
if (ret)
goto failed2;
- ret = mdev_register_device(&mbochs_dev, &mdev_fops);
+ ret = mdev_register_vfio_device(&mbochs_dev, &mdev_fops);
if (ret)
goto failed3;
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index cc86bf6566e4..d3029dd27d91 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -775,7 +775,7 @@ static int __init mdpy_dev_init(void)
if (ret)
goto failed2;
- ret = mdev_register_device(&mdpy_dev, &mdev_fops);
+ ret = mdev_register_vfio_device(&mdpy_dev, &mdev_fops);
if (ret)
goto failed3;
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 92e770a06ea2..744c88a6b22c 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1468,7 +1468,7 @@ static int __init mtty_dev_init(void)
if (ret)
goto failed2;
- ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
+ ret = mdev_register_vfio_device(&mtty_dev.dev, &mdev_fops);
if (ret)
goto failed3;
--
2.19.1
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